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int (^myBlock)(int) = ^(int num) {
return num * multiplier;
};
// for comparison
int (*fcnptr)(int);
int d = i % 10;
repeat(10, ^{ putc('0' + d);
});
void (^block)(void);
typedef void (^vstr_t)(char *);
typedef void (^workBlk_t)(void);
void AllLinesInFile(char *f, vstr_t block)
{
FILE *fp = fopen(f, "r");
if (!fp)
{
return;
}
char line[1024];
while (fgets(line, 1024, fp))
{
block(line);
}
fclose(fp);
}
@implementation NSArray (WWDC)
-(NSArray *)map: (id (^)(id)) xform
{
id result = [NSMutableArray array];
for (id elem in self)
{
[result addObject: xform(elem)];
}
return result;
}
-(NSArray *)collect: (BOOL (^)(id)) predicate
{
id result = [NSMutableArray array];
for (id elem in self)
{
if (predicate(elem))
{
[result addObject: elem];
}
}
return result;
}
// corner case: block literal in use with return type
id longLines = [allLines collect: ^BOOL (id item) {
return [item length] > 20;
}];
// corner case: block literal in use with return type
id longLines = [allLines collect: ^BOOL *(id item) {
return [item length] > 20;
}];
@end
// 1. block literal: ^{ ... };
// 2. block declaration: return_t (^name) (int arg1, int arg2, ...) NB: return_t is optional and name is also optional
// 3. block inline call ^ return_t (int arg) { ... }; NB: return_t is optional
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